The goal of the proposed research is to examine the relationship between socioeconomic status (SES), socioeconomic instability and overweight among young children of immigrants and children of natives. This topic is significant because over one in five U.S. children is the child of an immigrant, many of whom are at high risk of becoming overweight or obese. Yet little is known about weight trajectories for children of immigrants in middle childhood, the age when interventions might be most effective. In addition, research on the children of immigrants provides a unique opportunity to help resolve some of the inconsistencies in the literature on the socioeconomic-health gradient. One of the more enduring findings in the public health and demographic literature is that higher SES is associated with better health (Finch 2003). Yet the relationship between SES and child's weight status, a key indicator of health, varies across race and ethnic groups. The proposed research is innovative because it is one of the first studies to use nationally representative, longitudinal data-the Early Childhood Longitudinal Study-Kindergarten Cohort-to explore weight trajectory patterns among children of immigrants, but is also theoretically motivated, drawing on assimilation theory, nutrition theory, and social stratification theory to move beyond just a descriptive portrait of nativity status and obesity. A large proportion of Hispanics and Asians are immigrants or the children of immigrants. Yet the research literature in public health and epidemiology has only just begun to distinguish groups by nativity or generational status, and has not yet considered country of origin characteristics or nativity variation in the construct validity of educational attainment in research on the SES-gradient. Unlike prior studies we focus on both relative and absolute measures of SES to best assess the relationship between SES and obesity. By applying insights from sociology and demography about immigrants and their countries of origin, we address the question of race/ethnic disparities in children's health. The research will serve as a springboard for a larger project which will examine the behavioral and social psychological mechanisms underlying the SES-gradient, but also will examine some of the structural changes that tend t accompany shifts in SES that could be associated with different weight trajectories. PUBLIC HEALTH RELEVANCE: The goal of the proposed research is to examine the relationship between socioeconomic status (SES), socioeconomic instability and overweight among young children of immigrants and children of natives. The proposed research is significant because over one in five U.S. children is the child of an immigrant, many of whom are at high risk of becoming overweight or obese. In addition to having relevance to the health and well-being of children of immigrants, research on immigrant health focuses attention on the effects of the U.S. environment on the health of all children, immigrant or native.